The hack was made to present the hacked game like it was originally intended to be, with some altered placements of levels and how it contains the zones and events from Sonic & Knuckles. In some way, it could be considered a G/MD port of Sonic & Knuckles Collection.
The game plays identically to Sonic 3 & Knuckles. The player can either play as Sonic, Tails or Knuckles (Sonic and Tails can be separate or partnered). Sonic can do an insta-shield attack when pressing the jump button on mid-air. Doing the same for Tails lets him fly, and Knuckles can glide and climb up walls.
Become involved in the Sonic story of a lifetime as you help Sonic, Tails and Knuckles through the epic levels to defeat Dr. Robotnik as he pilots the death star-like Flying Egg and plans to destroy the planet!
In the amazing Sonic the Hedgehog 3 Complete you must battle hard to collect the golden rings and then use your powers to take on and defeat the evil doctor once and for all, making his Flying Egg crash to the ground!